[1]汪依妮,柳鑫,王健健,等.三工河流域不同植物群落细根对盐碱化的响应[J].应用与环境生物学报,2018,24(06):1229-1235.[doi:10.19675/j.cnki.1006-687x.2018.01045] WANG Yini,et al..Response of the fine roots of different plant communities to salinity in the Sangong River basin[J].Chinese Journal of Applied & Environmental Biology,2018,24(06):1229-1235.[doi:10.19675/j.cnki.1006-687x.2018.01045]

Throughout the whole growing season (from May to October 2010), sequential soil coring and ingrowth bag methods were adopted to investigate the vertical distribution, seasonal changes, decomposition dynamics, and turnover of fine roots, and their relationship with soil factors of five saline-alkali plant communities (Reaumuria songonica community, Alhagi sparsifolia community, Elaeagnus angustifolia community, Tamarix ramosissima community, and Phragmites australis community) in the Sangong River basin. Results showed that the fine root biomass increased initially, and decreased thereafter as soil layers deepened in the five studied communities. The fine root biomass reached its maximum in the 10–20-cm soil layer in all communities, except for P. australis. The fine root biomass of all five communities initially increased, but decreased thereafter from May to October, reaching its maximum in August or September, with values of 51.55, 93.09, 146.24, 57.95, and 419.34 g/m2, respectively. The fine root decomposition rate presented three distinct “fast-slow-fast” phases over the five-month long decomposition experiment, and all five decomposition rates were divided into the “slow group” of Peterson. The amount of fine root death, fine root decomposition, and fine root productivity were significantly different between communities: P. australis community > E. angustifolia community > A. sparsifolia community > T. ramosissima community > R. soongonica community. The range of fine root turnover rate was 1.41–1.98 times/a in the five communities, higher than the average value of 0.56 times/a observed in terrestrial ecosystems. Stepwise regression analysis showed that the soil pH, soil electrical conductivity, soil bulk density, and soil water content were the dominant factors or common dominant factors, and that the soil pH was the most important factor influencing the fine root distribution, decomposition, and turnover. Saline communities have a small fine root biomass, a slow decomposition rate, and a fast turnover rate; therefore the soil water content and the amount of salt present determine the distribution and dynamics of fine roots.